Lesson: Dilation and Isometries

Prerequisite Knowledge: Students should be familiar with reflections, rotations and translations. Students should be familiar with graphing on the coordinate plane.

Learning Objectives: Students will be able to identify and perform a dilation on the coordinate plane. Students will be able to understand the scale factor of dilation. Students will understand the concept of isometry and apply it to reflection, rotation and translation.

Key Ideas: Dilation (x,y) D scale of 4 (4x,4y)

The scale factor can refer to an enlargement or a reduction of a figure

Motivational Problem: On a coordinate plane plot the points A(-2,0) B(-2,2) C(-1,2) and D(0,-1). Perform the translation T(4, -2). Plot the new points and record the new coordinates labeling them A’B’C’. With the original figure multiple each x,y coordinate by 3. Plot and record the new coordinates labeling them A’’B’’C’’. Answer the following questions about the new figures:

Important Questions: What is a scalar?

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